A Farrari 458 Italia can move two people at speeds in excess of 200 MPH, the Superbus (pictured above) moves 23 people at speeds of 155 MPH, the newest Maglev train in Japan tops out at 312 MPH, with 14 cars each carrying 68 passengers (952 people). These are examples of bulk or batch movement of people.
Processing data, moving data, from one application to another. This occurs in a number of ways either as a singleton or a large set (batch), instantly, near-real time, delayed by minutes, in batches throughout the business day or in a large batch cycle at the close of the day. Each case has specific performance and throughput goals. Software performance engineering includes methods for batch processing.
Lets talk about batches…
Our complex business and IT systems of today still do a large amount of batch processing, moving data out of one system and into many more systems, with transformation and enhancements along the way. These can be internal systems in the Enterprise or external third party providers or even customers. I have noticed over the past few years that batch performance design has become (by accident) an iterative approach.
The original design goals were simply specified for the entire batch process, it must be completed by 06:00 EST. Often times, the batch critical path is not clear. There has been little thought to the throughput of each batch job (transaction per second). The iteration starts during the QA testing process when it is discovered that the current batch process will take 24 hours to process the days’ work. Someone finally did the math. The team did not know if it was designing a Farrari, a Superbus or a Maglev.
For the critical path batch processes you must define the required throughput. What are you moving? Invoices, orders, customers, transactions. How many of them do you have and what is the peak volume? What is your scalability approach and how do you achieve increases in throughput? Do you need to scale-up or scale-out?
You need to design the batch process to fit comfortably in the batch window and with room to grow. This year 500,000 invoices, next year is 750,000 invoices. How do you process the increase and stay within the window?
Software performance engineering Sample Questions
1 What are you processing?
2 How many steps (programs) are in the batch process?
3 What is the overall throughput?
4 What is the throughput of the individual programs?
5 What is the growth rate?
6 What is the peaking factor?
7 How will the programs scale with the load?
8 Have you identified the critical path throughput goals?
9 Are all the developers aware of the throughput goals?
10 How will you test and validate the throughput of each program?
Know your design goals
The barchettas were made in the 1940’s and 1950’s. An Italian style topless 2-seater sports car, designed and build for one purpose, to go fast. It was built for racing, weight and wind resistance were kept to a minimum, any unnecessary equipment was removed, no decoration. Doors were optional. Ferrari created one of the earlier models and other followed with the same style. The design team was focused on speed, they knew there were performance and response time goals for the car.